Beijing's liaison office chief has reiterated that reform for the 2017 chief executive election must adhere to the Basic Law, a stance previously taken to rule out public nomination.

The remarks by Zhang Xiaoming, quoted by a pan-democratic lawmaker who met him yesterday, were the first response by a mainland official to Occupy Central supporters' selection of three options for the poll, which all call for the public to have the right to nominate candidates.

Dr Joseph Lee Kok-long said he told Zhang the options "clearly show a strong aspiration for public nomination".

Zhang did not respond to his points one by one, "because we were just making our own points and there was good communication", Lee said.

"Director Zhang reiterated clearly the central government's stance. It was the same stance … that [the election] must fit the Basic Law."

Lee - the health services representative and the first democrat to enter the liaison office in Sai Wan since 2010 - was speaking after a 90-minute meeting behind closed doors.

It came two days after Occupy Central endorsed three proposals for a "civil referendum" on political reform next month. That decision was criticised by moderate pan-democrats for failing to give people a genuine choice.

Lee said he and Zhang also discussed remarks by National People's Congress chairman Zhang Dejiang in March.

He was referring to a statement by the national legislature chief that Beijing was "firmly supportive of Hong Kong's gradual democratic development in accordance with the Basic Law", and that failure to elect a patriotic ruler could have "disastrous consequences".

Lee was the first pan-democrat to meet Zhang since 10 pan-democrats met Beijing officials to discuss political reform in Shanghai a month ago.

Accountancy sector lawmaker Kenneth Leung, who also attended the Shanghai meeting, told the South China Morning Post on Wednesday that he would not meet liaison office representatives to discuss electoral reform before Occupy Central's "referendum" from June 20 to 22.

Other pan-democrats have yet to decide whether to accept an invitation to meet Zhang.